Crotalus Cerastes - Reproduction

Reproduction

Females produce up to 18 young, with an average of about 10 per litter. Like most other viperids, the young are born enveloped in thin embryonic membranes out of which they emerge shortly after being expelled from the mother. The young stay with their mother in a burrow for 7–10 days, shed for the first time, then leave their natal burrow. During this time, it is thought that the mother guards and protects them from predators.

Sidewinders mature at 2–3 years of age, are capable of reproducing annually, and give birth to live young. Some females skip reproductive opportunities. Some might even skip two years, if the food supply is scarce. Sidewinders mate in April through May and sometimes in fall. When the male and female mate, the male snake crawls along the female's back, rubbing her with his chin to stimulate or arouse her. The male then will wrap his tail around her tail and then will try to bring their clocque together. The clocque is a little flap that is near tail which is designed for mating and reproduction. If the female wants to mate, she will lift her tail and allow him to mate with her. The snakes can be mating for several hours, and if one of the snakes decides to move, the other is dragged along. Females might mate with several males in a season. Females give birth to 5-18 young in late summer to early fall. The young are born 6 to 8 inches long. The birth takes only 2 to 3 hours altogether. Within a few minutes after being born, the baby sidewinder escapes out of a thin transparent membrane. The young stay at their natal burrow for 7–10 days until they shed and then they disappear and have no future contact with their mother or their littermates. While the density of sidewinders can be up to 1 individual per hectare, individuals rarely encounter each other except during mating season.

Sidewinders have an extraordinarily accelerated life cycle, with natural life expectancies of females of about five years. Males may live quite a bit longer (max known natural life span of 13 years). Sidewinders can live more than 20 years when well fed in captivity (even females). Thus, it appears that energetics factor heavily into natural female mortality, whereas predation might be the primary pressure on males. In the wild, females often die of post-birth exhaustion, but the lives of sidewinders are also cut short because of predation, diseases, and vehicle encounters.